One thing: Betta fins are very delicate and easily torn by the edges on plastic plants. Take them out and run the edges along some old pantyhose, if it snags them then it shouldn't be in there. Or just go ahead and buy some new silk plants...he might be even happier cuz they'll be soft and comfy to sleep in.

Nav2008, If the water drops any distance it will create more flow so it would be better to have your water level higher..or you caould purchace a small filter ( made for small tanks) called a Azoo palm filter it willl cost you $10 ..it is a small filter that looks like a small power filter it is a sponge filter and you can adjust the flow rate..they make cool stuff for small tanks now..if you cant find it in LFS check out online (Doctor's Foster & Smith for one) as for water change in a small tank ..I have 6 small tanks ( as well as a 55 gal) they range from 3-6 Gallon..to kepp the water quality good I do a 25% water change every other day and once a week I take the little guys out , put them in a cup and vac the gravel and do a 25% water change...that seems to work pretty well..at least I haven't had any problems with my guys.